1. Field of the Invention
The present invention relates to a data switching processing method and apparatus for performing the switching of data units such as packets, frames, cells, etc., with addressing information included therein.
2. Description of the Related Art
In data switching networks, such as packet switching networks, frame relay switching networks, or cell switching networks, processing for switching is performed with a data unit, such as a packet, frame, or cell, as a unit, each data unit consisting of variable-length or fixed-length data and a header containing data addressing information appended to the data.
According to a prior art switching method, in switching processing equipment also, data is unconditionally transferred from the entrance to the exit side of the switching equipment with the variable-length or fixed-length data unit as a unit and in accordance with the addressing information included therein. This increases the complexity of processing at both the entrance and the exit side. Furthermore, for a data unit containing an error, it will be sufficient to only transfer the header from the entrance to the exit side, but in the above method, the whole data unit has to be transferred, which has been a major obstacle to the improvement of throughput.
Moreover, since congestion processing (discarding of data units, etc., in the event of congestion) is usually not performed at the entrance side, a buffer with a sufficient capacity has to be provided at both the entrance and the exit side.